From owner-freebsd-net@FreeBSD.ORG Sat Jan 25 01:07:06 2014 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 64F08F12; Sat, 25 Jan 2014 01:07:06 +0000 (UTC) Received: from mail-ie0-x22e.google.com (mail-ie0-x22e.google.com [IPv6:2607:f8b0:4001:c03::22e]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 28A581CA2; Sat, 25 Jan 2014 01:07:06 +0000 (UTC) Received: by mail-ie0-f174.google.com with SMTP id tp5so3701664ieb.33 for ; Fri, 24 Jan 2014 17:07:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=gImumYW6YoA0EdDGAf45MFg5hC8J9NJt+Z56uaTyos4=; b=B9iEgt/ByCAn5GipupuDDF1j/WiBFa0nnh6fAToxitQc/wCGhXLCASuGrQHAPO6u4j EofVOhsaohHgG4ttDJgsC3CkYX7CFWz6wfL4vANn/K1XwWPoE+5H64Nzq/erHcM1twG7 7GLb7kCSXwRONuvduLnoBTKOGsrFKEIwpPqGxmM3rtinJd+38lFhC5o9VjzalMSlzL0a Q6zBKuWrTjn78z7E7i/8xBwEMH5n7vzAhCdkL9IhkAklzJPMbfHqWgOeYMC2toZIShtW CCbNbTnHbejxTdSJAC7QFfpJXAWsHC7ZyPZBZMumHiKh1NuKHgVmcggiImfJ82HFBxdV 4cJg== MIME-Version: 1.0 X-Received: by 10.50.154.102 with SMTP id vn6mr7280929igb.1.1390612025611; Fri, 24 Jan 2014 17:07:05 -0800 (PST) Sender: jdavidlists@gmail.com Received: by 10.42.170.8 with HTTP; Fri, 24 Jan 2014 17:07:05 -0800 (PST) In-Reply-To: <179007387.16041087.1390608600325.JavaMail.root@uoguelph.ca> References: <179007387.16041087.1390608600325.JavaMail.root@uoguelph.ca> Date: Fri, 24 Jan 2014 20:07:05 -0500 X-Google-Sender-Auth: u0gVtKR1Id0TXsN2Cs3PnrBgPDQ Message-ID: Subject: Re: Terrible NFS performance under 9.2-RELEASE? From: J David To: Rick Macklem Content-Type: text/plain; charset=ISO-8859-1 Cc: freebsd-net@freebsd.org X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 25 Jan 2014 01:07:06 -0000 On Fri, Jan 24, 2014 at 7:10 PM, Rick Macklem wrote: > I would like to hear if you find Linux doing read before write when > you use "-r 2k", since I think that is writing less than a page. It doesn't. As I reported in the original test, I used an 8k rsize/wsize and a 4k write size on the Linux test and no read-before-write was observed. And just now I did as you asked, a 2k test with Linux mounting with 32k rsize/wsize. No extra reads, excellent performance. FreeBSD, with the same mount options, does reads even on the appends in this case and can't. random random KB reclen write rewrite read reread read write Linux 1048576 2 281082 358672 125687 121964 FreeBSD 1048576 2 59042 22624 10304 1933 For comparison, here's the same test with 32k reclen (again, both Linux and FreeBSD using 32k rsize/wsize): random random KB reclen write rewrite read reread read write Linux 1048576 32 319387 373021 411106 364393 FreeBSD 1048576 32 74892 73703 34889 66350 Unfortunately it sounds like this state of affairs isn't really going to improve, at least in the near future. If there was one area where I never thought Linux would surpass us, it was NFS. :( Thanks!